This invention relates to paper feeder apparatus and more particularly to a paper and envelope feeder apparatus for use with a printer or copier.
Paper feeders are widely employed and utilized as adjunct equipment to printers and copy machines. As is well known, many modern copy machines and printers have the ability to accommodate different sizes of paper by employing multiple trays or multiple feed mechanisms. In any event, many such machines do not provide the capability of changing paper size without difficult mechanical maneuvers. For example, in certain printers and copy machines, there is employed a single paper tray whereby a stack of papers of one size can be accommodated and utilized during the printing process. In the case of such machines, in order to change the size of the paper, the tray has to be removed with a new stack of papers of the requisite size placed in the tray. This, of course, is a relatively time consuming process.
In the case of other printers or copy machines these may include two or more trays, each one of which is adapted to accommodate different size paper and the particular size would be selected by the user during a printing or copying procedure. In any event, a great many printers are available on the market which do not have the capability of accommodating different paper sizes. Many prior art machines also include an input slot for feeding a single sheet of paper at a time. Hence, the prior art cognizant of these problems provided separate apparatus generally designated as paper feeders and which feeders were adapted to automatically feed paper into the printer or copier from one or more additional locations or trays which were associated with the paper feeder.
For examples of such apparatus, reference is made to U.S. Pat. No. 4,326,815 entitled Paper Feeding Apparatus and Method for Printing Apparatus issued on Apr. 27, 1982 to L. J. Kapp and assigned to the assignee herein. See also U.S. Pat. No. 4,407,597 entitled Paper Feeding Apparatus by L. J. Kapp and also assigned to the assignee herein.
Presently, there are printers which utilize a laser to perform a printing task. These printers are manufactured by different companies and as indicated are generally referred to as laser printers. The laser printer utilizes a drum upon which a raster scanning laser beam is directed, which laser beam writes an image on the photoconducting drum. The generated pattern then picks up particles of toner and transfers them to paper. Laser printers as provided by typical manufacturers normally have a paper feed mechanism which allows the user to insert paper into a slot or direct paper from a tray so that the paper is then utilized by the printer to furnish the hard copy. An example of such a laser printer is manufactured by the Canon Company and sold under the designation as the Canon LBP/CX. Other companies such as Hewlett Packard of Palo Alto, Calif., manufacture such a printer which is designated as the LaserJet. These are example of companies that manufacture laser printers and which printers are available for commercial sale.
In any event, as indicated above, a typical problem that exists with such printers is that these printers are normally associated with a single tray which can only accommodate one particular size of paper and in order to implement a paper change, the tray would have to be removed, a new stack of paper inserted into the tray, and then the tray is replaced to accommodate a different size paper. This particular problem is the type of problem described above and exists in regard to many commercially available printers and copiers. Apart from this consideration is the further factor that many of these printers as well as copiers are not capable of handling or accommodating envelopes. Such printers have the ability to print out addresses and other data which would be normally included on an envelope. Hence, a device for providing the automatic feeding of envelopes into a printer or copier mechanism is an extremely desirable feature. Thus, it is a desire to provide a paper and envelope feeder which is specifically designed to feed cut paper sheets and envelopes into a printer or a copier without modifying the basic printer or copier apparatus. The apparatus should be simple in structure and be completely compatible with the requirements, operating characteristics and paper handling capability of the associated printer or copier. The apparatus to be described provides two input paper trays, an input envelope tray and an output stacker as well as an access path to the paper feed slot of a commercially available laser printer. It is an object of the present invention to allow the printer to remain fully functional and capable of normal operation while utilizing the present apparatus. Hence, the additional feeder apparatus which is the subject matter of this invention does not interfere with normal printer operation while giving the printer the ultimate capability of utilizing different input paper trays as well as an envelope tray. The apparatus to be described is situated under the printer and essentially the printer mounts on and is supported by the apparatus to provide easy maintenance and optimum use. The entire paper feeder is controlled by means of a microcomputer or microprocessor unit. The microcomputer controls the drive units and mechanical controls while providing an interface between the paper feeder and the printer being utilized. The computer control mechanism includes paper path and envelope path sensors which are coupled directly to inputs of the micro computer to allow the unit to control the entire feed apparatus in an efficient and reliable manner.